【作者】 张晋铭；

【导师】 彭辉；

【作者基本信息】 中南大学 ， 控制科学与工程， 2010， 硕士

【摘要】 本文对具有时变和非线性特点的直流调速系统的控制策略进行了研究,针对常规PID控制器参数固定不变,不具备自适应的特点,将神经网络引入直流调速系统。采用小脑模型神经网络(CMAC)控制器与常规PD控制器相结合的自适应控制器,取代常规的PID或PI控制器,实现对直流电机的控制,并基于DSP来实现。本文采用瑞泰创新的TCETEK-F2812-A评估板作为系统开发平台,设计了直流电机的外围控制电路,充分利用TMS320F2812DSP片内集成的丰富的外设资源,简化系统的硬件电路设计,降低了硬件成本,并利用DSP的高速运算能力来实现较复杂的控制策略。本文详细介绍了系统的软硬件设计方法和本文所采用的自适应控制策略,并对实物进行了实际控制实验。针对实验中出现采用常规CMAC前馈控制器控制效果不佳的现象,对常规CMAC前馈控制器的工作原理和直流调速系统的特点进行了分析,将系统的动态误差取代系统的给定量作为CMAC网络的输入信号,即将CMAC前馈控制器改为反馈控制器。并针对改成CMAC反馈控制器后,系统长时间运行后会出现过学习导致系统震荡的现象进行了分析,将CMAC控制器的权值修正进行约束以及在稳态精度内对其泛化能力进行相应约束后,即可得到比较理想的控制效果,且能防止过学习现象。经过大量实验表明：本文设计的基于DSP的自适应直流调速系统,充分利用了CMAC较好的非线性逼近能力,在线学习速度快,输出误差小的优点,提高了直流调速系统的整体性能指标。并且能适应环境或系统参数的变化,控制品质高,自适应能力强,因此,具有很高的实际应用和推广价值。更多还原

【Abstract】 This paper mainly focuses on the control strategy of the time-variant nonlinear DC speed control system. To cope with the characteristics of constant parameter and nonadaptive of the traditional PID, the neural network has been brought in. The traditional PID/PI controller is replaced by the combination of CMAC and PD controller, and it is applied on the DC motor based on DSP.With the TCETEK-F2812-A evaluation board as the system development platform, the periphery control curcuits of DC motor are designed. By fully using the rich resourses of the chip, the hardware design has greatly been simplified, so does the cost. It is also a good way to achieve the complicated control strategy by using the high-speed computing power of DSP.The details of the hardware and software design method and the adopted adaptive control strategy are given, on which the experiments are carried. To deal with the poor performance appeared in the experiments, the analysis of the conventional CMAC working principle and characteristics of DC speed control system has been carried out. The dynamic error replaces the given value as the input signal of CMAC, that is, the feedforward is changed into the feedback. Moreover, aiming at the over-study condition causing oscilliations through running a long time period, constraints are added to the correction weight and generalized ability in the steady status. The results show that it has an ideal control outcome, and the over-study is inhibited.Based on abundant experiment results, the following conclusion can be made. The proposed adpative DC speed control system based on DSP has a good overall performance by using the advantage of CMAC, which are good nonlinear approaching ability, fast online studying rate and small output error. What’s more, it can adapt to the environment or changes of parameters, and has an excellent performance and superious adaptation ability. Therefore, it is worthy of practical application and popularization.更多还原